pa9tv wrote:* frequency should be in Hz.* how about centerfreq, bandwidth instead of upper/lower bounds.

I agree with the CF / BW combination, and this is also how we are building the IARU database at the moment.Frequencies are ALWAYS in Hz in any formal communication with ITU, so indeed that should always be the case.

g4dpz wrote:A satellite may have more than one alias, depending in the source: AMSAT / Celestrak

I agree, if only to catch dominant spelling variants. or ISS/Zarya case.

g4dpz wrote:Should telemetry be a child of beacon

True, you can view telemetry as a specialization of a beacon. In any case, if they share properties, these should be equally named.I would not make it a child element in the xml, because i cant see any physical dependency other than the satellite. Telemetry can be used as a beacon in a rf listeners case, i agree. How would you differentiate between a CW beacon only and a telemetry-beacon only situation.In a client it would require testing for the existence of properties of the beacon, or adding an extra element 'beacon-implementation' which existence can be tested.

In the underlying object model you could make telemetry a derivation of beacon, but how do you model a transponder into this. If you want this to drive your receiver, the objects could all implement an interface with freq, mode, bw. But this will be up to the implementors of the clients. If you do it in java, it would be my preferered approach.

multiple approaches:- fixed modulation types AM, FM, APT, etc. which need additions on new modulation forms.- describe the first detector, and optional the second.- free field to describe popular name of modulation.